/*
 Copyright (C) 2010 Kristian Duske

 This file is part of TrenchBroom.

 TrenchBroom is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 TrenchBroom is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with TrenchBroom. If not, see <http://www.gnu.org/licenses/>.
 */

#include "Vbo.h"

namespace tb::render
{

Vbo::Vbo(const GLenum type, const size_t capacity, const GLenum usage)
  : m_type{type}
  , m_capacity{capacity}
{
  contract_pre(m_type == GL_ELEMENT_ARRAY_BUFFER || m_type == GL_ARRAY_BUFFER);

  glAssert(glGenBuffers(1, &m_bufferId));
  glAssert(glBindBuffer(m_type, m_bufferId));
  glAssert(glBufferData(m_type, static_cast<GLsizeiptr>(m_capacity), nullptr, usage));
}

void Vbo::free()
{
  contract_pre(m_bufferId != 0);
  glAssert(glDeleteBuffers(1, &m_bufferId));
  m_bufferId = 0;
}

Vbo::~Vbo()
{
  contract_pre(m_bufferId == 0);
}

size_t Vbo::offset() const
{
  return 0;
}

size_t Vbo::capacity() const
{
  return m_capacity;
}

void Vbo::bind() const
{
  contract_pre(m_bufferId != 0);

  glAssert(glBindBuffer(m_type, m_bufferId));
}

void Vbo::unbind() const
{
  contract_pre(m_bufferId != 0);

  glAssert(glBindBuffer(m_type, 0));
}

} // namespace tb::render
